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Flume, mail # user - Data Lineage


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Re: Data Lineage
Connor Woodson 2013-02-05, 01:51
You will want to look at the Serializer
<http://flume.apache.org/FlumeUserGuide.html#event-serializers>component.
The default serializer is TEXT, which will only write out the body of your
event discarding all headers. You can switch to one of the other
serializers, or if none of them suit your purpose you are able to create
your own that, for instance, could write the event in JSON format thus
preserving the headers.

(Only two serializers are currently documented. You can see
here<https://github.com/apache/flume/tree/trunk/flume-ng-core/src/main/java/org/apache/flume/serialization>all
of the ones currently in Flume (it looks like there's only one
additional one there, and it might be exactly what you're looking for)).

If you want more detail on creating a custom serializer, or how to use one
of the existing ones, please ask.

- Connor
On Mon, Feb 4, 2013 at 7:38 AM, Tzur Turkenitz <[EMAIL PROTECTED]> wrote:

> Hello All,****
>
> ** **
>
> In my company we are worried about data lineage. Big files can be split
> into smaller files (block size) inside HDFS, and smaller files can be
> aggregated into larger files. We want to have some kind of control
> regarding data lineage and the ability to map source files to files in
> HDFS. Using interceptors we can add various keys like timestamp, static,
> file header etc.****
>
> ** **
>
> After a file has been processed and inserted into HDFS, do those keys
> still exist and viewable if I choose to cat the file in HADOOP? (I did cat
> the files and didn’t see any of the keys) Or the keys only exist during the
> process and are not saved into the file.****
>
> ** **
>
> Alternatively is it possible to append those keys into the file using
> Flume's built in component?****
>
> ** **
>
> I appreciate the help,****
>
> Tzur****
>
> ** **
>